Most of the better Christians I've been closest to tend to avoid such a metaphor ... most of the time. I have heard it maybe several dozen times in my life--by Christians--genuine Christians--as a metaphor. And Qx and I have heard it in psychological discussions--even by Christians--a fair amount. NO ONE involved or looking on assumed the one using the metaphor really thought XYZ meant to replace Christ as a person's savior.
Rescuing someone from breaking through the pond ice or from a burning building makes "A" the savior of "B" and may be called so. No one assumes "B" suddenly replaces Jesus with "A" as their eternal savior.
I never said, ‘No one has ever heard a Christian call a fellow human being their savior.’ I said ***I*** have never heard a Christian call a fellow human being/sinner their savior. That happens to be the truth.